基于单条后向轨迹的滞留时间场和污染物排放强度场,设计了一种可以评估该轨迹对污染物的平流输送强度参数.利用2011年6-8月光明项CO和O3浓度资料对该参数进行了验证,进而分析了该观测时段平流输送对光明顶污染物的影响;此外将O3浓度分成3档,利用改进的PSCF(Potential source contribution function)方法分析了各档浓度对应的源区分布.结果表明:(1)平流输送评估参数与污染物浓度的变化具有很好的一致性,表明平流输送对光明顶污染物浓度的变化具有重要作用.其中,安徽、湖北和江西三省交界区域的城市群向光明顶输送的污染物占到输送总量的一半以上;(2)光明顶O3浓度〉55×10^-9、(30-55)×10^-9、〈30×10^-9 时所对应的主要源区分别为华北及长三角发达工业区、黄山西南方向的工业区、较远的南部沿海地区;(3)影响光明顶污染物浓度变化的输送类型可以分为秸秆燃烧输送、发达工业区气团输送、西南方向气团输送和海洋性气团输送4种类型,对应的污染物浓度(CO/O3)(×10^-9)依次为474.47/72.50、221.16/57.71、86.31/30.41、51.67/27.45.
A parameter aimed to evaluate pollutants advective transport intensity was designed based on the residence time field of backword trajectory and pollutants emission intensity field. The parameter was evaluated by using the data of CO (carbon monoxide) and O3 (ozone) from June to August 2011 in Bright Summit of Mt Huang, and then the contributions of pollutants advective transport to this site were calculated. The potential source distributions of O3, which was assorted into three bins of O3 levels were investigated by a modified potential source contribution function (PSCF). Results showed that the advective transport parameters well reproduced the variation of CO and O3 concentrations respectively, indicating that advective transport played great impact on the change of CO and O3 at the site. The transport intensities of urban regions surrounding the border of Anhui,Hubei and Jiangxi province account for more than half of total intensities. The potential sources of 03 bins (〉55× 10^-9, (30-55)× 10^-9, 〈30× 10^-9)at Bright Summit were mainly attributed to developed industrial zones in North China and Yangtze River Delta, industrial zones in the southwest and south and east China Sea, respectively. There were four advective transport types during the observations, which were classified into transport from crop residue burning, developed industrial zones, air masses originated from southwest and air masses originated from ocean. The CO/O3 concentration ratios (×10^-9) of the four transport types were 474.47/72.50, 221.16/57.71, 86.31/30.41 and 51.67/27.45, respectively.